Mobile phones today become an essential entity for one and all and so, for any mobile based
application there is great reception. In this scenario making a mobile phone operated crane is
a good idea. Conventionally, wireless-controlled crane use RF circuits, which have the
drawbacks of limited working range, limited frequency range and limited control. Use of a
mobile phone for robotic control can overcome these limitations. It provides the advantages
of robust control, working range as large as the coverage area of service provider. No fear of
interfering with other controllers and we can have as much as 12 controls.
Although the appearance and capabilities of crane vary vastly, all robots share the features of
a mechanical, movable structure under some form of control. The control of crane involves
three distinct phases: perception, processing and action. Generally, the processing is done by
the on-board microcontroller (ATMEGA8) and the task (action) is performed using motors or
with some other actuators.
1.1 Project overview
In the present project the crane is controlled by a mobile phone which makes a call to
the mobile phone attached to the crane. In the course of call if any button is pressed a
tone corresponding to the button pressed is heard at the other end of the call. This
tone is called DTMF tone, the crane perceives this DTMF tone with the help of
phone stacked in the crane. The processing of the received tone is done by Atmega8
microcontroller with the help of DTMF decoder, HT9170. The decoder decodes the
DTMF tone in to its equivalent binary digit and this binary number is sent to the
microcontroller. The microcontroller is pre-programmed to take a decision for any
given input. The microcontroller outputs its decision to motor drivers to drive the
motors in order to have forward or backward motion or a turn. Any mobile which
makes a call to the mobile phone stacked in the robot will act as remote. So, this is a
simple crane project which even does not require the construction of receiver and
transmitter kits, but has an innovated application of cell phone and robust control.
Dual-tone multi-frequency (DTMF) signalling is used for telephone signalling over
the line in the voice-frequency band to the call switching centre. The version of
DTMF used for telephone tone dialling is known by the trademarked term touchtone.
DTMF assigns a specific frequency (consisting of two separate tones) to each
key so that it can easily be identified by a microprocessor. The signal generated by a
DTMF encoder is algebraic summation, in real time, of the amplitudes of two sine
(cosine) waves of different frequencies, i.e. pressing '5' will send a tone made by
adding 1336Hz and 770Hz to the other end of the line.
History of remote controlled vehicles
The first remote control vehicle
This propeller-driven radio controlled boat, built by Nikola tesla in 1898, is the original
prototype of all modern-day uninhabited aerial vehicles and precision guided weapons. In
fact, all remotely operated vehicles in air, land or sea. Powered by lead-acid batteries and an
electric drive motor, the vessel was designed to be maneuverer alongside a target using
instructions received from a wireless remote-control transmitter. Once in position, a
command would be sent to detonate an explosive charge contained within the boat's forward
compartment. The weapon's guidance system incorporated a secure communications link
between the pilot's controller and the surface-running torpedo in an effort to assure that
control could be maintained even in the presence of electronic countermeasures. To learn
more about tesla's system for secure wireless communications and his pioneering
implementation of the electronic logic-gate circuit read 'Nikola tesla ' guided weapons &
computer technology', tesla presents series part3, with commentary by Leland Anderson.
1.2 Block diagram
Figure 1.2 shows the block diagram of the mobile operated crane. The important components
of this project are DTMF decoder, microcontroller and drive.
FIG.1: BLOCK DIAGRAM
The block diagram of the mobile phone operated crane consists of the following blocks. They
' DTMF Decoder
' Motor Driver.
1.3 Circuit diagram
FIG.2: CIRCUIT DIAGRAM
An MT8870 series DTMF decoder is used here. All types of the MT8870 series use digital
counting techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code output.
The built-in dial tone rejection circuit eliminates the need for pre-filtering. When the input
signal given at pin 2 (IN-) in single-ended input configuration is recognised to be effective,
the correct 4-bit decode signal of the DTMF tone is transferred to Q1 (pin 11) through Q4
(pin 14) outputs. Q1 through Q4 outputs of the DTMF decoder (IC1) are connected to port
pins PA0 through PA3 of microcontroller (IC2) after inversion by N1 through N4,
respectively. Outputs from port pins PD0 through PD3 and PD7 of the microcontroller are
fed to inputs IN1 through IN4 and enable pins (EN1 and EN2) of motor driver L293D,
respectively, to drive two geared DC motors. Switch S1 is used for manual reset. The
microcontroller output is not sufficient to drive the DC motors, so current drivers are required
for motor rotation. The L293D is a quad, high-current, half-H driver designed to provide
bidirectional drive currents of up to 600 mA at voltages from 4.5V to 36V. It makes it easier
to drive the DC motors. The L293D consists of four drivers. Pins IN1 through IN4 and OUT1
through OUT4 are input and output pins, respectively, of driver 1 through driver 4. Drivers 1
and 2, and drivers 3 and 4 are enabled by enable pin 1 (EN1) and pin 9 (EN2), respectively.
When enable input EN1 (pin 1) is high, drivers 1 and 2 are enabled and the outputs
corresponding to their inputs are active. Similarly, enable input EN2 (pin 9) enables drivers 3
1.4 Working of the circuit
In order to control the robot, you need to make a call to the cell phone attached to the robot
(through head phone) from any phone, which sends DTMF tunes on pressing the numeric
buttons. The cell phone in the robot is kept in 'auto answer' mode. (If the mobile does not
have the auto answering facility, receive the call by 'OK' key on the rover-connected mobile
and then made it in hands-free mode.) So after a ring, the cell phone accepts the call. The
DTMF tones thus produced are received by the cell phone in the robot. These tones are fed to
the circuit by the headset of the cell phone. The MT8870 decodes the received tone and sends
the equivalent binary number to the microcontroller. According to the program in the
microcontroller, the robot starts moving. When you press key '2' (binary equivalent
00000010) on your mobile phone, the microcontroller outputs '10001001' binary equivalent.
Port pins PD0, PD3 and PD7 are high. The high output at PD7 of the microcontroller drives
the motor driver (L293D). Port pins PD0 and PD3 drive motors M1 and M2 in forward
direction. Similarly, motors M1 and M2 move for left turn, right turn, backward motion and
1.5 Hardware requirements
The main components of the hardware section of our project are given as:
' Crystal Oscillator
' DTMF decoder IC (MT8870)
' Motor driver
' DC Motor
' Resistors, Capacitors
' Hex inverter.
1.6 Action Performs To Corresponding Key
T1: ACTION PERFORMED CORRESPONDING TO KEY
1.7 Software requirements
' Proteus 7.0
Proteus 7.0 is a virtual system modelling(VSM) that combines circuit simulation,
animated components and microprocessor models to co-simulate the complete
microcontroller based designs.
In summary, proteus 7.0 is the program to use when you want to simulate the
interaction between software running on a microcontroller and any analog or digital
electronic device connected to it.
' AVR Studio
It is a full software development environment with an editor, simulator, Programmer,
etc. it comes with own integrated C compiler the AVR GNU C Compiler (GCC). As
such you do not need a third party C Compiler. It provides a single environment to
develop programs for both the 8-bits, 32-bits, and ARM cortex-M series of
2 DTMF DECODER MT8870
2.1 DUAL TONE MULTI FREQUENCY (DTMF):
Dual-tone multi-frequency (DTMF) signaling is used for telecommunication signaling over
analog telephone lines in the voice-frequency band between telephone handsets and other
communications devices and the switching center. The version of DTMF used for telephone
tone dialing is known by the trademarked term Touch-Tone (cancelled March 13, 1984), and
is standardized by ITU-T Recommendation Q.23. It is also known in the UK as MF4. Other
multi-frequency systems are used for signaling internal to the telephone network. As a
method of in-band signaling, DTMF tones were also used by cable television broadcasters to
indicate the start and stop times of local commercial insertion points during station breaks for
the benefit of cable companies. Until better out-of-band signaling equipment was developed
in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during
the commercial breaks of cable channels in the United States and elsewhere.
2.2 Mobile phone keypad
The contemporary keypad is laid out in a 3x4 grid, although the original DTMF keypad had
an additional column for four now-defunct menu selector keys. When used to dial a telephone
number, pressing a single key will produce a pitch consisting of two simultaneous pure tone
sinusoidal frequencies. The row in which the key appears determines the low frequency, and
the column determines the high frequency. For example, pressing the key will result in a
sound composed of both a 697 and a 1209 hertz (Hz) tone. The original keypads had levers
inside, so each button activated two s. The multiple tones are the reason for calling the
system multifrequency. These tones are then decoded by the switching center to determine
which key was pressed.
2.3 DTMF keypad frequencies
DTMF signalling is used for telephone signalling over the line in the voice-frequency band to
the call switching centre. The version of DTMF used for telephone tone dialling is known as
Touch-Tone. DTMF assigns a specific frequency (consisting of two separate tones) to each
key so that it can easily be identified by the electronic circuit. The signal generated by the
DTMF encoder is a direct algebraic summation, in real time, of the amplitudes of two sine
(cosine) waves of different frequencies, i.e., pressing '5' will send a tone made by adding
1336 Hz and 770 Hz to the other end of the line. The tones and assignments in a DTMF
system are shown in Table2 (T2).
Frequencies 1209Hz 1336Hz 1477Hz 1633Hz
697Hz 1 2 3 A
770Hz 4 5 6 B
852Hz 7 8 9 C
941Hz * 0 # D
T2: DTMF TONES AND ASSIGNMENT
The MT8870D/MT8870D-1 is a complete DTMF receiver integrating both the band split
110633132012 DTMF DECODER(MT8870)
filter and digital decoder functions. The filter section uses switched capacitor techniques for
high and low group filters; the decoder uses digital counting techniques to detect and decode
all 16 DTMF tone-pairs into a 4-bit code. The features of MT 8870 are:
' Complete DTMF Receiver
' Low power consumption
' Internal gain setting amplifier
' Adjustable guard time
' Central office quality
' Power-down mode
' Inhibit mode
' Backward compatible with MT8870C/MT8870C-1
The applications of MT 8870 are:
' Receiver system for British Telecom (BT) or CEPT Spec (MT8870D-1)
' Paging systems
' Repeater systems/mobile radio
' Credit card systems
' Remote control
' Personal computers
' Telephone answering machine
110633132012 DTMF DECODER(MT8870)
2.5 Functional block diagram:
FIG.4: FUNCTIONAL BLOCK DIAGRAM
The MT8870D/MT8870D-1 monolithic DTMF receiver offers small size, low power
consumption and high performance. Its architecture consists of a band split filter section,
which separates the high and low group tones, followed by a digital counting section which
verifies the frequency and duration of the received tones before passing the corresponding
code to the output bus.
2.5.1 Filter Section
Separation of the low-group and high group tones is achieved by applying the DTMF signal
to the inputs of two sixth-order switched capacitor band pass filters, the bandwidths of which
correspond to the low and high group frequencies. The filter section also incorporates notches
at 350 and 440 Hz for exceptional dial tone rejection. Each filter output is followed by a
110633132012 DTMF DECODER(MT8870)
single order switched capacitor filter section which smooths the signals prior to limiting.
Limiting is performed by high-gain comparators which are provided with hysteresis to
prevent detection of unwanted low-level signals. The outputs of the comparators provide full
rail logic swings at the frequencies of the incoming DTMF signals.
2.5.2 Decoder section
Following the filter section is a decoder employing digital counting techniques to determine
the frequencies of the incoming tones and to verify that they correspond to standard DTMF
frequencies. A complex averaging algorithm protects against tone simulation by extraneous
signals such as voice while providing tolerance to small frequency deviations and variations.
This averaging algorithm has been developed to ensure an optimum combination of immunity
to talk-off and tolerance to the presence of interfering frequencies (third tones) and noise.
When the detector recognizes the presence of two valid tones (this is referred to as the 'signal
condition' in some industry specifications) the 'Early Steering' (EST) output will go to an
active state. Any subsequent loss of signal condition will cause EST to assume an inactive
state (see 'Steering Circuit').
110633132012 DTMF DECODER(MT8870)
2.5.3 Steering Circuit
FIG.5: STEERING CIRCUIT
Before registration of a decoded tone pair, the receiver checks for a valid signal duration
(referred to as character recognition condition). This check is performed by an external RC
time constant driven by Est. Logic high on Est. causes VC to rise as the capacitor discharges.
Provided signal condition is maintained (Est. remains high) for the validation period (tGTP),
VC reaches the threshold (VTSt) of the steering logic to register the tone pair, latching its
corresponding 4-bit code into the output latch. At this point the GT output is activated and
drives VC to VDD. GT continues to drive high as long as Est. remains high. Finally, after a
short delay to allow the output latch to settle, the delayed steering output flag goes high,
signaling that a received tone pair has been registered. The contents of the output latch are
made available on the 4-bit output bus by raising the three state control input (TOE) to logic
high. The steering circuit works in reverse to validate the interdigit pause between signals.
Thus, as well as rejecting signals too short to be considered valid, the receiver will tolerate
110633132012 DTMF DECODER(MT8870)
signal interruptions (dropout) too short to be considered a valid pause. This facility, together
with the capability of selecting the steering time constants externally, allows the designer to
tailor performance to meet a wide variety of system requirements.
2.5.4 Guard Time Adjustment
In many situations not requiring selection of tone duration and interdigital pause, the simple
steering circuit shown. Component values are chosen according to the formula:
2.6 Pin connections and description
FIG.6: PIN DIAGRAM
110633132012 DTMF DECODER(MT8870)
The above figure shows pin description.
T3: TABLE OF DTMF DESCRIPTION
110633132012 DTMF DECODER(MT8870)
2.7 DTMF output
T4: TABLE OF DTMF OUTPUT
110633132012 HEX INVERTER
3. 74LS04 HEX INVERTERS
These devices contain six independent inverters. The IC package is as follows.
FIG.7: HEX INVERTER PIN DIAGRAM
The functional table at each inverter is as follows:
T5: FUNCTIONAL TABLE OF INVERTOR
4.1 Over view
The Atmel ATmega8 is a low-power CMOS 8-bit microcontroller based on the AVR RISC
Architecture. By executing powerful instructions in a single clock cycle, the ATmega8
achieves throughputs approaching 1MIPS per MHz, allowing the system designer to optimize
power consumption versus processing speed.
The Atmel core combines a rich instruction set with 32 general purpose working registers.
All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two
independent registers to be accessed in one single instruction executed in one clock cycle.
The resulting architecture is more code efficient while achieving throughputs up to ten times
faster than conventional CISC microcontrollers.
The ATmega8 provides the following features: 8 Kbytes of In-System Programmable Flash
with Read-While-Write capabilities, 512 bytes of EEPROM, 1 Kbyte of SRAM, 23 general
purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with
compare modes, internal and external interrupts, a serial programmable USART, a byte
oriented Two wire Serial Interface, a 6-channel ADC (eight channels in TQFP and QFN/MLF
packages) with 10-bit accuracy, a programmable Watchdog Timer with Internal Oscillator, an
SPI serial port, and five software selectable power saving modes. The Idle mode stops the
CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue
functioning. The Power down mode saves the register contents but freezes the Oscillator,
disabling all other chip functions until the next Interrupt or Hardware Reset. In Power-save
mode, the asynchronous timer continues to run, allowing the user to maintain a timer base
while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and
all I/O modules except asynchronous timer and ADC, to minimize switching noise during
ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest
of the device is sleeping. This allows very fast start-up combined with low-power
consumption. The device is manufactured using Atmel's high density non-volatile memory
technology. The Flash Program memory can be reprogrammed In-System through an SPI
serial interface, by a conventional non-volatile memory programmer, or by an On-chip boot
program running on the AVR core. The boot program can use any interface to download the
application program in the Application Flash memory. Software in the Boot Flash Section
will continue to run while the Application Flash Section is updated, providing true Read-
While-Write operation. By combining an 8-bit RISC CPU with In-System Self-
Programmable Flash on a monolithic chip, the Atmel ATmega8 is a powerful microcontroller
that provides a highly-flexible and cost-effective solution to many embedded control
applications. The ATmega8 is supported with a full suite of program and system development
tools, including C compilers, macro assemblers, program simulators, and evaluation kits.
4.2 Pin diagram
FIG.8: PIN DIAGRAM OF ATMEGA8
' High-performance, Low-power Atmel8-bit Microcontroller
' Advanced RISC Architecture
' 130 Powerful Instructions ' Most Single-clock Cycle Execution
' 32 ?? 8 General Purpose Working Registers
' Fully Static Operation
' Up to 16MIPS Throughput at 16MHz
' On-chip 2-cycle Multiplier
' High Endurance Non-volatile Memory segments
' 8Kbytes of In-System Self-programmable Flash program memory
' 512Bytes EEPROM
' 1Kbyte Internal SRAM
' Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
' Data retention: 20 years at 85??C/100 years at 25??C
' Optional Boot Code Section with Independent Lock Bits In-System Programming by Onchip
Boot Program True Read-While-Write Operation
' Programming Lock for Software Security
' Peripheral Features
' Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode
' One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode
' Real Time Counter with Separate Oscillator
' Three PWM Channels
' 8-channel ADC in TQFP and QFN/MLF package
' 6-channel ADC in PDIP package
' Byte-oriented Two-wire Serial Interface
' Programmable Serial USART
' Master/Slave SPI Serial Interface
' Programmable Watchdog Timer with Separate On-chip Oscillator
' On-chip Analog Comparator
' Special Microcontroller Features
' Power-on Reset and Programmable Brown-out Detection
' Internal Calibrated RC Oscillator
' External and Internal Interrupt Sources
' Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and Standby
' I/O and Packages
' 23 Programmable I/O Lines
' 28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF
' Operating Voltages
' 2.7V - 5.5V (ATmega8L)
' 4.5V - 5.5V (ATmega8)
' Speed Grades
' 0 - 8MHz (ATmega8L)
' 0 - 16MHz (ATmega8)
' Power Consumption at 4 MHz, 3V, 25 C
' Active: 3.6mA
' Idle Mode: 1.0mA
' Power-down Mode: 0.5??A
4.4 Pin description
VCC Digital supply voltage.
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit).
The Port B output buffers have symmetrical drive characteristics with both high sink and
source capability. As inputs, Port B pins that are externally pulled low will source current if
the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition
becomes active, even if the clock is not running. Depending on the clock selection fuse
settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the
internal clock operating circuit. Depending on the clock selection fuse settings, PB7 can be
used as output from the inverting Oscillator amplifier. If the Internal Calibrated RC Oscillator
is used as chip clock source, PB7...6 is used as TOSC2...1 input for the Asynchronous
Timer/Counter2 if the AS2 bit in ASSR is set.
Port C (PC5..PC0) Port C is an 7-bit bi-directional I/O port with internal pull-up resistors
(selected for each bit). The Port C output buffers have symmetrical drive characteristics with
both high sink and source capability. As inputs, Port C pins that are externally pulled low will
source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
PC6/RESET If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the
electrical characteristics of PC6 differ from those of the other pins of Port C. If the
RSTDISBL Fuse is programmed, PC6 is used as a Reset input. A low level on this pin for
longer than the minimum pulse length will generate a Reset, even if the clock is not running.
generate a Reset.
Port D (PD7...PD0) Port D is an 8-bit bi-directional I/O port with internal pull-up resistors
(selected for each bit). The
Port D output buffers have symmetrical drive characteristics with both high sink and source
Capability. As inputs, Port D pins that are externally pulled low will source current if the
pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes
active, even if the clock is not running.
RESET Reset input. A low level on this pin for longer than the minimum pulse length will
generate a reset, even if the clock is not running.
AVCC AVCC is the supply voltage pin for the A/D Converter, Port C (3...0), and ADC
(7..6). It should be externally connected to VCC, even if the ADC is not used. If the ADC is
used, it should be connected to VCC through a low-pass filter. Note that Port C (5...4) use
digital supply voltage, VCC.
AREF AREF is the analog reference pin for the A/D Converter.
ADC7..6 In the TQFP and QFN/MLF package, ADC7...6 serve as analog inputs to the A/D
converter. These pins are powered from the analog supply and serve as 10-bit ADC channels.
4.5 Crystal oscillator
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can
be configured for use as an On-chip Oscillator, Either a quartz crystal or a ceramic resonator
may be used. The CKOPT Fuse selects between two different Oscillator amplifier modes.
When CKOPT is programmed, the Oscillator output will oscillate a full rail-torail swing on
the output. This mode is suitable when operating in a very noisy environment or when the
output from XTAL2 drives a second clock buffer. This mode has a wide frequency range.
When CKOPT is unprogrammed, the Oscillator has a smaller output swing. This reduces
power consumption considerably. This mode has a limited frequency range and it cannot be
used to drive other clock buffers. For resonators, the maximum frequency is 8MHz with
CKOPT unprogrammed and 16MHz with CKOPT programmed. C1 and C2 should always be
equal for both crystals and resonators. The optimal value of the capacitors depends on the
crystal or resonator in use, the amount of stray capacitance, and the electromagnetic noise of
The L293 and L293D are quadruple high-current half-H drivers. The L293 is designed to
provide bidirectional drive currents of up to 1 A at voltages from 4.5 V to 36 V. The
L293D is designed to provide bidirectional drive currents of up to 600-mA at voltages
from 4.5 V to 36 V. Both devices are designed to drive inductive loads such as relays,
solenoids, dc and bipolar stepping motors, as well as other high-current/high-voltage
loads in positive-supply applications. All nputs are TTL compatible. Each output is a
complete totem-pole drive circuit, with a Darlington transistor sink and a pseudo-
Darlington source. Drivers are enabled in pairs, with drivers 1 and 2 enabled by 1,2EN
and drivers 3 and 4 enabled by 3,4EN. When an enable input is high, the associated
drivers are enabled and their outputs are active and in phase with their inputs. When the
enable input is low, those drivers are disabled and their outputs are off and in the highimpedance
state. With the proper data inputs, each pair of drivers forms a full-H (or
bridge) reversible drive suitable for solenoid or motor applications. On the L293, external
high-speed output clamp diodes should be used for inductive transient suppression. A
VCC1 terminal, separate from VCC2, is provided for the logic inputs to minimize device
power dissipation. The L293and L293D is characterized for operation from 0??C to 70??C.
6. Problems Encountered
Although the concept & design of the project seemed perfect, there were some problems
faced while actual implementation:
' Connecting hands free of cell phone to DTMF decoder IC input:
There were several types of hands free cords available in the market, the right one had
to be chosen from them. Several ways to break up the cords and connect them to the
input of IC8870 were tried & some were newly developed by us(e.g. connecting audio
jack of PC's speakers to the cell phone with help of an extender).
Finally hands free cord's 'earplugs' were removed & resulting set of wires were
connected in an appropriate manner to the Decoder IC's input
' Selection of mobile phone:
At first, latest cell phone (android screen touch) were tried. But they couldn't give any
output. Several cell phones were tested with their respective hands free cords.
The older version phones like Samsung GTE1001 were found more suitable for the
purpose. Finally Samsung was used
7. Result Analysis
7.1 Power supply
ATMEGA8 controller is operating at 5V. So we have to give the supply of 5V to
ATMEGA8. The 5V power generating circuit is made by using 7805 as shown in figure.
The power supply port's output is of12V it is convert in to 5V using 7805 and the output of
7805 directly given to ATMEGA8 which is 5v.
' Wireless control
' Surveillance System.
' Vehicle Navigation with use of 3G technology.
' Takes in use of the mobile technology which is almost available
' This wireless device has no boundation of range and can be controlled as
far as network of cell phone
' Cell phone bill.
' Mobile batteries drain out early so charging problem.
' Cost of project if Cell phone cost included.
' Not flexible with all cell phones as only a particular, cell phone whose
earpiece is attached can only be used.
Remote control vehicles have various scientific uses including hazardous
environments, working in the Deep Ocean, and space exploration. The majority of
the probes to the other planets in our solar system have been remote control
vehicles, although some of the more recent ones were partially autonomous. The
sophistication of these devices has fuelled greater debate on the need for manned
spaceflight and exploration. The voyager I spacecraft is the first craft of any kind
to leave the solar system. The Martian explorers spirit and opportunity have
provided continuos data about the surface of mars since January 3.2004.
' Military and law Enforcement
Military usage of remotely controlled military vehicles dates back to the first half
of 20th century. Soviet red army used remotely controlled teletanks during 1930s
in the winter war and early stage of World War II.
Remote control vehicles are used in law enforcement and military engagement for
some of the same reasons. The exposure to hazards is mitigated to the person who
operates the vehicle from a location of relative safely. Remote controlled vehicles
are used by many police department bob-squads to defuse or detonate explosives.
See dragon runner, military robot.
' Search and rescue
Unmanned aerial vehicles will likely play an increased role in search and rescue in
the United States. Slowly other European countries are thinking about making use
of these vehicles in case of natural calamities & emergencies. This was
demonstrated by the successful use of UAVs during the 2008 hurricanes that
struck Louisiana and Texas.
' Recreation and hobby
See radio-controlled model. Small scale remote control vehicles have long been
popular among hobbyists. These include on-road cars, off-road trucks, boats,
airplanes and even helicopters. The 'robots' now popular in television shows such
as robot wars
8.4 Future scope
' IR sensors
' Password protection
' Alarm phone dialer
' Adding camera
Conventionally, wireless-controlled robots use RF circuits, which have the drawbacks of
limited working range, limited frequency range and limited control. In our project with the
use of a mobile phone for crane control can overcome these limitations. It provides the
advantages of robust control, working range as large as the coverage area of the service
provider, no interference with other controllers and up to twelve controls. Although the
appearance and capabilities of robots vary vastly, all robots share the features of a
mechanical, movable structure under some form of control. The control of robot involves
three distinct phases: reception, processing and action. Generally, the preceptors are sensors
mounted on the robot, processing is done by the on-board microcontroller or processor, and
the task (action) is performed using motors or with some other actuators. So the motive is that
to increase the range of remote controlled products. For this mobile phone operated control is
best because we can globalize our project & no limitation of range.
I collect our require information from following websites'..
1. 'The 8051 microcontroller and embedded systems' By Muhammad Ali
mazidi and Janice gillispie mazidi. Pearson Education.
2. R. Sharma, K. Kumar, and S. viq, 'DTMF based remote control system,'
IEEE international conference ICIT2006.
3. Emerging trends in robotics and communication technologies, 2010
International conference on robotics & control system.
Source: ChinaStones - http://china-stones.info/free-essays/engineering/catch-place-crane-cellphone.php